Installation Overview

Installation Overview

Mysa for Baseboards is designed for straightforward installation. This guide walks you through the complete process — from unboxing to pairing with the Mysa app.

Before You Begin

Warning Mysa for Baseboards connects to high-voltage (120/240V) wiring. Always turn off power at the breaker and verify with a voltage tester before touching any wires.

Check local building codes — some regions require a licensed electrician for line-voltage thermostat installation.

Tip The Mysa app provides step-by-step installation guidance. Download the free Mysa app from the App Store (iOS) or Google Play (Android), create your Mysa account, and have your Wi-Fi network name and password ready.

Use the Mysa Compatibility Checker to confirm your system works with Mysa for Baseboards before starting.

What You'll Need

Required:

• Medium Phillips screwdriver
• Voltage tester
• Smartphone with the Mysa app

Recommended:

• Small Phillips screwdriver
• Wire strippers
• Pliers

Installation Steps

1. Turn Off Power

Switch off the circuit breaker for your heater. Use a voltage tester at the thermostat wires to confirm power is off.

Warning Never assume power is off. Always test with a voltage tester before touching any wires.

If you don't have a voltage tester: Before turning off the breaker, turn your existing thermostat all the way up and confirm heat is coming from your heater. Then turn off the breaker and wait — if the heater cools down, power is off. If you're completely unsure which breaker controls your heater, you can turn off all power at your main panel. Do this during daylight hours.

Tip Installing multiple thermostats? Do one at a time to minimize risk.

2. Follow the In-App Installation Guide

The Mysa app includes a personalized wiring guide that covers dozens of different wiring configurations. This is the best way to install your thermostat correctly.

Open the Mysa app and start the installation process. The app will walk you through:

1. Identifying your existing wiring
2. Removing your old thermostat
3. Connecting wires one at a time — matching each old thermostat wire to the correct Mysa wire lead
4. Mounting and pairing

Before disconnecting anything, take a photo of your existing wiring for reference.

Verify you have 4+ wires. Most setups have two bundles (4–6 wires total) — one bringing power in (line) and one going out to the heater (load). If you only see 2 wires, check inside the gang box for extra capped wires tucked inside.

3. General Wiring Reference

The in-app guide provides personalized instructions, but here's a general reference:

For 240V:

• L1 ← Line (L1) from breaker
• L2/N ← Second line (L2) from breaker, joined with L2 going to heater
• Load ← Load wire going to heater

For 120V:

• L1 ← Line (L) from breaker, joined with line going to heater
• L2/N ← Neutral (N) from breaker, joined with neutral going to heater
• Load ← Load wire going to heater

Use the wire nuts included with Mysa (do not reuse existing wire nuts). Push wires firmly into wire nuts and give a gentle tug to confirm they're secure.

4. Mount, Attach, and Restore Power

1. Attach Mysa's base plate to the gang box using the included mounting screws
2. Align the thermostat display with the base plate and press gently until it clicks into place
3. Turn the circuit breaker back on

The thermostat display should light up. V2 and Lite will show the Bluetooth pairing symbol when ready. Legacy V1 will show a Wi-Fi symbol.

5. Complete Pairing

Continue following the in-app guide to:

1. Connect to the thermostat via Bluetooth
2. Connect to your 2.4 GHz Wi-Fi network
3. Select your heater type (Baseboard, Fan-forced, or Radiant)
4. Name your thermostat

Installation Troubleshooting

Thermostat won't power on

1. Remove the faceplate and look for a green LED on the base plate
2. If no green LED: The L1 supply wire (usually black, from breaker) isn't connected to Mysa L1. Turn off power and check the connection.
3. If green LED is lit: Mysa is receiving power. Remove the faceplate for 3–5 minutes, then reattach it. If the display still doesn't light up, contact support.

Heat won't shut off

This is often caused by the heater wire being connected to L1 instead of Load.

• The L1 supply wire (usually black, from breaker) should connect to Mysa L1
• Heater wires should connect between Mysa Load and L2/N — not to L1

Turn off power, review your wiring, and correct any mistakes. If the heater still won't shut off, contact support.

No heat coming from the heater

The most common cause is an incorrect connection between the heater load wire and Mysa Load.

• Check that the heater load wire is securely connected to Mysa Load
• Give the wire nut a gentle tug to confirm it's tight

H2 error code (V2 and V1 only)

Mysa didn't detect a heater between Load and L2/N.

1. Turn off power at the breaker
2. Check that all wires are properly secured in each wire nut — as more wires go into a wire nut, connections can loosen
3. Turn power back on and verify the error clears

Reboot Methods

If you need to restart your thermostat:

Soft reboot: Hold the up and down arrows (or buttons) for 10 seconds.

Hard reboot: Turn off the circuit breaker, wait 30 seconds, then turn it back on.

Installation Video

Watch the installation video — filmed with Mysa for Baseboards - V2, but the steps are the same for Lite.

User Manuals

• Mysa for Baseboards - V2 User Manual (PDF)
• Mysa LITE for Baseboards User Manual (PDF)

Need Help?

• Installation questions: install@getmysa.com
• General support: support@getmysa.com